An arc generated in a load where a power is consumed may cause damage to a power supply or the load. Although it is preferred to substantially prevent the generation of the arc, the arc may occur due to various factors. Therefore, technical efforts have been continued to detect the generation of arc to block the consecutive generation thereof.
In particular, for a plasma process where a RF power is used, the generated arc may damage a plasma chamber and contaminate the materials to be processed. In this regard, technologies have been suggested to detect the arc generated in the chamber and to rapidly block it. For example, there is a process comprising detecting unexpected changes in a reflected power, checking whether an arc is generated or not, and blocking or reducing a RF power supplied. However, it is difficult to increase its feasibility since the arc generated in the plasma chamber does not necessarily lead to the increase in the reflected power.
A semiconductor fabrication process using plasma requires very high precision. Accordingly, there is a need for a method and an apparatus to precisely detect the arc generated in the chamber and rapidly control the supplying of power.